Upgrading from Java 17 to 21

"Java 21 is chock-full of great features and if you're coming all the way from 17, there's a plethora of additions to use and get used to, but it's all for naught if you can't actually update. In this #RoadTo21 episode, we discuss all you need to know to update from Java 17 to 21: API changes that may require you to update your code (like the introduction of sequenced collections or bug fixes in Double/Float::toString and IdentityHashMap), ongoing deprecations (threading, security manager, finalization, and more) and changes in networking (like earlier URL validation and HTTP timeouts), encoding (UTF-8 by default and changes in date/time/unit formatting), the runtime (like removed options class loading), and tooling (like new warnings). We'll also go beyond the nitty-gritty details and see the bigger picture of how to best prepare and execute your Java and 3rd party updates by talking about inside.java, release notes, Quality Outreach, and much more."